Supporting Information

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1 Electronic Supplementary Material (ESI) for anoscale. This journal is The Royal Society of Chemistry 2014 Supporting Information From gold porphyrin to gold nanoparticles: application to glucose oxidation Kamal Elouarzaki a, Alan Le Goff a, Michael olzinger a, Charles Agnès b, Florence Duclairoir b, Jean-Luc Putaux c and Serge Cosnier a* a Univ. Grenoble Alpes, DCM, F Grenoble, France. CRS, DCM, F Grenoble, France b Institut anosciences et Cryogénie, Laboratoire de Chimie Inorganique et Biologique, UMR E3 CEA UJF, CEA Grenoble, 17 rue des Martyrs, Grenoble, France c Centre de Recherches sur les Macromolécules Végétales (CERMAV-CRS), UPR 5301, BP 53, Grenoble Cedex 9, France affiliated with Université Joseph Fourier and member of Institut de Chimie Moléculaire de Grenoble and Institut Carnot Polyat

2 Experimental 1. Materials Commercially available reagents, α-d-glucose, anhydrous aoac, AuCl 4, afion, 1- methyl-2-pyrrolidinone (MP), and potassium hydroxide (KO) were of analytical grade and purchased from Sigma-Aldrich. Commercial grade thin Multi-Walled Carbon anotubes (MWT) (9.5 nm diameter, purity >95%), obtained from anocyl were used as received without any further purification step. Deuteroporphin IX dimethyl ester was purchased from ABCR. All other reagents, solvents, acids, and bases were of special grade and were used as received. 2. Preparation of Gold(III) Porphyrin Complexes The synthesis of the gold(iii) porphyrins was conducted under an inert atmosphere. The (DPDE)Au(III) complexes were prepared according to the following protocol: AuCl4 (91 mg, 0.27 mmol) and anhydrous aoac (73 mg, 0.88 mmol) were dissolved in acetic acid (5 ml). The mixture was protected from light and stirred for 10 min at room temperature. Deuteroporphin IX dimethyl ester (50 mg, 0.11 mmol) was added and the mixture was heated to 120 C over 4 h under argon. Complete metallation of the porphyrins was checked by disappearance of two Q bands of 2 (DPDE) using UV-Vis spectroscopy. Upon removal of the solvent under vacuum, the residue was dissolved in C 2 Cl 2 (50 ml). The organic phase was washed with saturated aqueous a 2 CO 3 and water. The organic phase was dried over MgSO 4 and evaporated. The crude mixture was purified by column chromatography with C 2 Cl 2 as eluant to remove unreacted compounds. Finally, (DPDE)Au(III) was then collected using a C 2 Cl 2 /MeO (99:1, v/v) mixture, affording the desired porphyrin as a reddish-purple solid (55 mg, mmol, 68 %).

3 2 3 C C 4 Au 3 C C 3 9 6' 7' CO 2 C CO 2 C 3 8' 8 5 MR δ (400 Mz; CDCl 3 ) : (3s, 4, ), 9.1 (s, 2, 2-4), 4.52 (t, 4, 6-6 ), 3.77 (s, 6, 8-8 ), 3.69 (s, 6, 5-9), 3.52 (s, 6, 1-3), 3.34 (t, 4, 7-7 ). UV-vis (CCl 3 ) max /nm ( mm -1 cm -1 ): 388 (120), 507 (15), 543 (22). ESI-MS m/z (acetonitrile): [(DPDE)Au(III)] General Methods Ultrapure water was obtained from a Milli-Q Purelab UQ (Elga) with a resistivity of 18.2 MΩ cm -1. Electrochemical measurements were performed at 20 ºC with an Autolab electrochemical analyzer (Eco Chemie, Utrecht, The etherlands) controlled by GPES software (Eco Chemie). X-ray photoelectron spectroscopy (XPS) measurements were carried out using a Surface Science Instruments (SSI) spectrometer employing monochromatic Al K radiation as the X-ray source. Electrodes for XPS measurements were fabricated using the following procedure: MWCTs (5 mg) were added to 1 ml of MP solvent containing 1 mg of the product (without afion ). The suspension was homogenized by an ultrasonic generator for 30 min. A portion (50 µl) of this suspension was dropped onto carbon felts. The solvent was removed under reduced pressure. MR spectra were recorded on a Bruker AVACE 400 operating at Mz for 1. ESI mass spectra were recorded with a Bruker APEX-Qe ESI FT-ICR mass spectrometer. UVvisible spectra were recorded with a Carry 1 spectrophotometer with a quartz cuvette (1 cm thickness).

4 The morphology of the MWCT electrodes was investigated by scanning electron microscopy (SEM) using a Zeiss ULTRA 55 FESEM equipped with the GEMII column with a beam booster (anotechnology Systems Division, Carl Zeiss TS Gmb, Germany). For transmission electron microscopy (TEM) observation, drops of dilute MWCT/(DPDE)Au(III) suspension in TF was deposited onto glow-discharged carboncoated electron microscopy grids and allowed to dry. The samples were observed using a Philips CM200 microscope (FEI Company, illsboro, OR, USA) operating at 80 kv. Micrographs were recorded on Kodak SO163 films. The samples used for electrochemical investigations or modification were prepared for TEM by scraping off the deposited MWCTs films from the GC electrodes and dispersed by sonication in TF for 2 min. Then, a drop of this suspension was put onto a Cu grid and allowed to dry in air. 3. Electrochemical Measurements Cyclic voltammetry (CV) was performed in a conventional three-electrode cell equipped with a glassy carbon (GC) electrode (geometric area = cm 2 ), a platinum wire counterelectrode and a saturated calomel electrode (SCE) as reference electrode for aqueous media. The electrochemical experiments, performed in organic media, were carried out in a threeelectrode electrochemical cell under a dry argon atmosphere and in a glove box ([O 2 ] < 20 ppm). A Pt wire placed in a separated compartment was used as counter electrode, and the Ag/AgO 3 10 mmol L -1 in DMF + TBAP (0.1 M) served as reference electrode. Potentials given are referred to this (Ag/AgO 3 ) electrode. The GC electrodes were polished with 2 µm diamond paste, purchased from Presi (France), followed by rinsing thoroughly with Milli-Q water using ultrasound. After further rinsing with acetone and ethanol, the GCs were dried at room temperature. Electrocatalytic experiments were performed in aqueous KO solutions at p = 13. All E 1/2 values reported in this work were determined from cyclic voltammogram as an average of the oxidative and reductive peak potentials (E p,a +E p,c )/2. The aqueous solutions were deoxygenated by purging with argon prior to each experiment and an argon flow was kept over the solution during the whole experiment. 4. Fabrication of MWCT/(DPDE)Au(III) electrodes

5 MWCT/(DPDE)Au(III) electrodes were fabricated using the following procedure: MWCTs (5 mg) were added to 1 ml of MP solvent containing 1 mg of the (DPDE)Au(III) complex and 5 µl afion (the afion solution contains 5% afion, 25% 2-propanol, 25% n-propanol, 45% water). The suspension was homogenized by an ultrasonic generator for 30 min. The resulting supernatant was used as catalyst ink. For electrochemical investigations, a portion (20 µl) of this suspension was dropped onto a freshly polished GC disk electrode (3 mm in diameter). The solvent was removed under reduced pressure.